You are not to reap the aftergrowth of your harvest or gather the grapes of your untended vines. The land must have a year of complete rest.
Jewish Publication Society of America Version (JPS1917) - Leviticus 25:5 >That which groweth of itself of thy harvest thou shalt not reap, and the grapes of thy undressed vine thou shalt not gather; it shall be a year of solemn rest for the land.